These projects are focused on the discovery and development of new fundamental materials, derived from smectite clay minerals and related layered structures, for use in environmental protection and restoration. Our goal is to develop economically and technically feasible materials that are useful for (1) removing, immobilizing and concentrating organic contaminants present in water, and (2) converting organic contaminants into less toxic forms. In this proposal we will emphasize ambient and low temperature conversions of toxicants, and the development of modified clay adsorbents that will augment current clay barrier technology for the containment of pollutant chemicals, as well as water treatment technology for removing contaminants from groundwater, leachate and industrial waste streams. Our strategy is based on the chemical modification of clay minerals and related structures using rational surface chemical methods to produce novel adsorbents and catalysts. This approach takes advantage of the fact that clays are economically practical as well as chemically and structurally diverse. Additionally, many of the clays studied in this project are components of soils so that aspects of the technologies developed herein may be applicable to in situ restoration of contaminated soils. These research projects have three major goals. First, to continue our efforts to design chemically modified pillared clays for the removal of organic pollutants from contaminated water. Secondly, to evaluate the efficacy of specific modified clays in reducing transport of organic contaminants through clay barriers. The third goal is to utilize clay supported biomemitic and chemical conversions to achieve ambient and low temperature transformations of toxicants into less toxic and more biodegradable forms.